Q1: usual talk about my academic past, interests and career aspirations.
Q2: the recruiter asked about my hobbies, in order to - I suppose - gain some sort of insight into my personality
Q3: idiotic puzzle (or "logic question", as the H.R. receuiter said) to solve in a few minutes. Something about measuring four liters of liquid in a single try whilst only having a 3lt and 5lt jar.